There exists a continuing need for electronic and computer devices to operate at faster speeds, with lower power, and smaller size. In particular, portable devices (e.g., personal digital assistants, mobile telephones, digital audio, and the like) rely on low power operation to improve battery life. However, these needs can be at odds with each other. For example, achieving lower power can, in some instances, prevent speed improvements of the device.
Size, performance, and power consumption of semiconductor devices are important to achieving the above goals for electronic and computer devices. Semiconductor devices (e.g., integrated circuits) are comprised of a number of components or devices. The size, performance, and power goals can be attained by further reducing component size while increasing the number of components present on the device. Generally, semiconductor devices are reduced in size by shrinking feature sizes and device dimensions. The number of components are increased, also referred to as density, and tracked by integration levels. However, scaling or shrinking semiconductor devices can have negative consequences, such as increased power loss due to, for example, increased leakage. With respect to semiconductor transistor devices, these devices are under constant pressure to reduce channel length as a mechanism to shrink device size. However, reducing the channel length requires increased channel doping levels to achieve a suitable threshold voltage. But, the increased doping levels can also cause increased leakage.
What is needed are systems and methods of fabrication that create scalable semiconductor transistor devices without substantially increasing low power standby leakage.